I did the same thing from the same company, on my Extra cab 84. I was having a horrible clunk noise and sometimes vibrations. turns out it was the U-joint in the front that was busted. I went through the same dilemma and came to the same conclusion. Called South Bay up gave them my measurements, picked up my one piece drive line the next day and bolted it right in. Smooth, quite, better response that the stock multi-link stuff. And I asked him to use the spicer joints. That was three years ago now with out any problems, never hit it on any rocks either.
Haven't looked back either.
It was quite a thrill driving over highway 17 on just my front drive line.
